セッション埋め込み正規表現

$viewVal = preg_replace( "/(href=\"[^>\?\":]*)\?([^>\?\"]*\"[^>\?\"]*>)/i", "$1?$si&$2", $viewVal );
$viewVal = preg_replace( "/(href=\"[^>\?\":]*)(\"[^>\?\"]*>)/i", "$1?$si$2", $viewVal );
$viewVal = preg_replace( "/<form[^>]*>/i", "$0<input type=\"hidden\" name=si value=\"$si\">", $viewVal );